Version Information

When I plug in my encrypted USB flash drive, Windows asks me if I want to format it. Is 
there a way to prevent that? 
 
Yes, but you will need to remove the drive letter assigned to the device. For information on how to 
do so, see the question 
‘I encrypted a non-system partition, but its original drive letter is still visible 
in the ‘My Computer’ list.’
 
 
 
How do I remove or undo encryption if I do not need it anymore? How do I permanently 
decrypt a volume? 
 
Please see the section 
How to Remove Encryption
. 
 
 
What will change when I enable the option ‘Mount volumes as removable media’?
 
Please see the section 
Volume Mounted as Removable Medium
.  
 
Do I have to “wipe” free space and/or files on a TrueCrypt volume?
Remark: to "wipe" = to securely erase; to overwrite sensitive data in order to render them unrecoverable. 
If you believe that an adversary will be able to decrypt the volume (for example that he will make 
you reveal the password), then the answer is yes. Otherwise, it is not necessary, because the 
volume is entirely encrypted.
 
 
How does TrueCrypt know which encryption algorithm my TrueCrypt volume has been 
encrypted with? 
Please see the section 
Encryption Scheme
 (chapter 
Technical Details
). 
 

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134 
Technical Details 
Notation 
C
Ciphertext block 
D
K
()
Decryption algorithm using encryption/decryption key 
K
E
K
() 
Encryption algorithm using encryption/decryption key 
K 
 
H
()
 
 
Hash function 
i 
 
Block index for 
n
-bit blocks; 
n
is context-dependent 
K
Cryptographic key 
P 
 
Plaintext block 
^ 
Bitwise exclusive-OR operation (XOR) 
⊕ 
Modulo 2
n
addition, where 
n
is the bit size of the left-most operand and of the 
resultant value (e.g., if the left operand is a 1-bit value, and the right operand is a 
2-bit value, then: 1 
⊕
0 = 1; 1 
⊕
1 = 0; 1 
⊕
2 = 1; 1 
⊕
3 = 0; 0 
⊕
0 = 0; 0 
⊕
1 = 1;
0 
⊕
2 = 0; 0 
⊕
3 = 1) 
⊗
Modular multiplication of two polynomials over the binary field GF(2) modulo 
x
128
+
x
7
+
x
2
+
x
+1 (GF stands for Galois Field) 
|| 
Concatenation

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135